Compartment for maintaining a clean production environment

ABSTRACT

The invention relates to a compartment  10  having a space  32  segregated from air outside the compartment and capable of housing a product apparatus for assembly of, for example, semiconductor devices and integrated circuit packages in a “clean” environment. The compartment  10  includes panels  16  to segregate the air inside the compartment  10  from the surrounding environment. At the front of the compartment  10,  there is a top access panel  12  and a bottom access panel  14  to access a production apparatus (not shown) which is houseable or storable within a space  32  for such apparatus defined within the compartment  10.    
     Where it is desired to place a plurality of similar compartments  10  adjacent to one another to provide a production line, an opening  18  can be included in one or both of the side panels  16  for transfer of processed material, such as leadframes for assembling integrated circuit packages, from one production apparatus to another, housed in respective adjacent compartments  10.  Thus the or each compartment  10  provides an individual clean space for carrying out a particular step of a production process. It is not therefore necessary to provide a single, massive, clean room.

FIELD OF THE INVENTION

[0001] The invention relates to a compartment for carrying out processes which require an environment with a relatively high degree of cleanliness, such as processes for assembling semiconductor devices and integrated circuit packages.

BACKGROUND AND PRIOR ART

[0002] Traditionally, large clean rooms with cleanliness levels of below 10,000 or 100,000 particles 0.5 microns or larger per cubic meter of air (hereinafter referred to as class 10,000 and 100,000 respectively) is required to provide the clean air needed for the assembly, packaging and testing of integrated circuit packages. Electrical risers are commonly installed in the clean room to supply the necessary electrical and gas supplies to the semiconductor producing equipment.

[0003] Such clean rooms are very expensive to set up and to maintain. Due to increased automation of manufacturing and assembly processes, it would be advantageous to reduce the size of the environment wherein the clean air is maintained so as to minimize the set-up and maintenance costs required for a traditional clean room.

[0004] In U.S. Pat. No. 4,934,920 relating to “An Apparatus for Producing Semiconductor Device”, an apparatus is described to provide a more dust-free environment for the production of semiconductor devices. The apparatus comprises a dust-proof cover which shields the semiconductor chips and the lead frame from ambient air and a dust collecting means for sticking air out of the dust-proof cover to suck dust from the interior of the dust-proof cover. Whilst it serves to remove dust generated by the discharge of dust from the molding process, it does not solve ale problem of performing the whole manufacturing process, which may include a whole production line involved in the semiconductor assembly process, in an environment that is cleaner than its surroundings.

SUMMARY OF THE INVENTION

[0005] It is an object of the invention to seek the mitigate the disadvantages of the prior art.

[0006] Accordingly, the invention provides a compartment having a space segregated from air outside the compartment and is capable of storing a production apparatus, comprising panels defining the space, an air transmission passage channeling air into the space, air filtering means disposed between the air transmission passage and the space to cleanse air entering from the air transmission passage, and an air outlet to allow air to be expelled from the space, whereby the compartment is adapted continuously to maintain air within the compartment cleaner than the air outside the compartment.

[0007] Using the invention, it is possible to provide a compartment wherein one or more production apparatuses in which a manufacturing process is carried out may be segregated from the surrounding environment. Means may provided to maintain the space within the or each compartment at a level of cleanliness that is higher than the surrounding environment so as to obviate the need for a traditional large clean room to carry out the manufacturing processes.

[0008] It will be convenient to hereinafter describe the invention in greater detail by reference to the accompanying drawings which illustrate one embodiment of the invention. The particularity of the drawings and the related description is not to be understood as superseding the generality of the broad. Identification of the invention as defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The drawings represent a preferred embodiment of the invention by way of illustration only wherein:

[0010]FIG. 1 is an isometric view of a compartment according to the preferred embodiment of the invention.

[0011]FIG. 2 is a front elevation view of the compartment of FIG. 1.

[0012]FIG. 3 is a side elevation view of the compartment looking from direction A of FIG. 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

[0013]FIG. 1 is an isometric view of a compartment 10 according to the preferred embodiment of the invention. FIG. 2 is a front elevation view of the compartment of FIG. 1. The compartment 10 includes panels 16 to segregate the air inside the compartment 10 from the surrounding environment. At the front of the compartment 10, there is a top access panel 12 and a bottom access panel 14 to access a production apparatus (not shown) which is houseable or storable within a space 32 for such apparatus within the compartment 10.

[0014] Where it is desired to place a plurality of compartments 10 adjacent to one another to accommodate a production line, an opening 18 can be included on one or both of the side panels 16 for transfer of processed material, such as lend frames for assembling integrated circuit packages, from one production apparatus to another, housed in respective adjacent compartments 10.

[0015] At the top (as viewed) of the compartment 10, there is an air transmission passage, which may be in the form of a ventilation duct 20, to introduce air from an air-generating means, such as an air conditioner, into the space 32 in the compartment 10. Alternatively, a blower 29 may directly draw air from the surrounding environment. It is this preferred, but not necessary, that the air introduced by the air-generating means is substantially dean. The compartment 10 includes a blower 29 and air filter 30 (see FIG. 3) to purify air entering the space 32 from the ventilation duct 20. The air filter is preferably a HEPA filter of a grade of class 1,000 or less.

[0016] Whilst clean air is introduced into the compartment 10, it is necessary for air within the space 32 to be expelled from the compartment 10, due to contamination from the manufacturing process and other factors. Thus, an air outlet, such as a ventilation outlet 22, for air to enter it through a return path 23, is implemented to allow air within the space 32 to escape while at the same time, more air is being fed into the space 32 via the ventilation duct 20.

[0017] Additionally, various trunkings can be included to allow cabling links to the production apparatus within each compartment 11. For example, an electrical trunking 21 may be included to run electrical cables along the top of the compartment and into the production apparatus in the compartment 10. There may also be various gas ducts 24 to channel gases generally used in a semiconductor manufacturing process into the production apparatus, such as compressed air or nitrogen.

[0018] Optionally, display means such as a liquid crystal display (LCD) monitor 26 may be included to the compartment 10 and mounted unto a mounting arm 28. The display means 26 may be used to display production parameters production progress and/or other information to monitor the production process. The mounting arm 28 preferably includes at its distal end a roller 32 and a guide rail 34 (see FIG. 3) so that the display means 26 is movable to various positions along a production line of similar compartments.

[0019]FIG. 3 is a side elevation view of the compartment looking from direction A of FIG. 2 in particular, sectional views of the ventilation duct 20, ventilation outlet 22 and cable trunking 21 are shown.

[0020] It will be understood that air from the ventilation duct 20 is drawn into the space 32 within the compartment 10 by means of a blower 29. Located between the blower 29 and the space 32 is an air filter 30 that filters air that is blown into the space 32. The air filter 30 seeks to maintain the cleanliness of the air inside the space 32 to preferably class 1,000 or better, i.e. less than 1,000 particles 0.5 microns or larger per cubic meter of air. The air in the space 32 leaves the space 32 into the ventilation output 22 through a return path 23 that is formed between the ventilation outlet 22 and the space 32. Due to the pressure formed in the space 32 by the blower 20 forcing air into the space 32, the air would tend to escape through the return path 23 into the ventilation outlet 22 owing to a pressure differential between the ventilation duct 20 and the ventilation outlet 22. Nevertheless, to increase the air-flow pressure differential, it is possible to include a suction fan (not shown) at a point along the ventilation outlet 22 to force air out of the space 32, via the ventilation outlet 92. The suction fan may be in the ventilation outlet 22 or at its entry or exit.

[0021] As regards the display means 26 mounted on the mounting arm 28, there is a roller 32 mounted on the distal end of the mounting arm 28, which is guided along the side of the compartment 10 by a guide rail 34. This function is most useful when a plurality of compartments are arranged side-by-side to form a production life. When the guide rail 34 of each adjacent compartment is aligned and interconnected with that of an adjacent one, the mounting arm 28 and display means 26 may be slid from one compartment to another by an operator, depending on the location of the operator, along the production line. A communications cable linking the display means 26 to a computer processing information for display i3 provided to extend along the plurality of compartments covered by the display means 26.

[0022] When a number of similar compartments 10 are aligned side-by-side to form a production line, and suitably interconnected, the openings 18 should also be aligned such that processed material may be passed from a production apparatus within one compartment to a production apparatus in an adjacent compartment. A typical production line for integrated circuit packages would include one or more die-bonders, snap-cures ovens, buffers, strip-based plasma systems, wire-bonders, molding machines, trim and form machines, and strip testers.

[0023] Each component in the production line may preferably be housed in a separate compartment 10 to maintain the clean processing environment within each space 32. A compartment 10 has interengagement moons whereby it may be connected with a similar compartment in a manner to provide that each space 32 is segregated from outside (ambient) air, and to that end the ventilation ducts 10 and outlets 22 of adjacent interconnected compartments 10 may be releasably engageable as by a push-fit connection. Conveying means (not shown) such as rollers for transporting leak frames may be included to automate the transfer of processed material from one apparatus to another, the processed material passing through tip openings 18. The separation of production of each manufacturing component into a separate compartment 10 has the advantage of modularity, so that different components in the production line may be mixed and matched according to manufacturing requirements with minimal re-orientation of production equipment or machines. A modular production line is thereby provided.

[0024] The panels 12, 14, 16 of the compartment 10 may be made of fiberglass; or other suitable material. The material may be opaque with a selected transparent viewing area, or wholly transparent, in which event the processes being carried out can be more easily monitored.

[0025] It would be appreciated that the invention provides the incorporation of embedded facilities in the form of a compartment with a controlled environment for one or more equipment in the production line. By enclosing the equipment with a compartment that is self contained with clean dry air, electrical, gas and communication network supplies, the cleanliness level required of the rest of the room wherein the equipment is held can be reduced.

[0026] The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the above description. 

1. A compartment having a space segregated from air outside the compartment and capable of housing a production apparatus, comprising: panels defining the space; an air transmission passage adapted for channeling air into the space; air filtering means disposed between the air transmission passage and the space to cleanse air entering from the air transmission passage; and an air outlet to allow air to be expelled from the space; whereby the compartment is adapted continuously to maintain air within the compartment cleaner than air outside the compartment.
 2. A compartment according to claim 1, wherein a plurality of compartments are assemblable adjacent to one another to form a production line.
 3. A compartment according to claim 2, wherein the compartments are releasably interengagably connectable to form a production line.
 4. A compartment according to claim 3, wherein the compartment is sized to accommodate one production apparatus in a production line consisting of a plurality of production apparatuses.
 5. A compartment according to claim 4, wherein there is conveying means within each compartment to convey a workpiece processed by each production apparatus from one production apparatus to another.
 6. A compartment according to claim 5, wherein openings are disposed in each compartment and aligned in the production line for passing processed material from one compartment to the next.
 7. A compartment according to any one of claims 4 to 8, wherein a production apparatus in a compartment along the production line can be substituted without reorientation of the compartments.
 8. A compartment according to any one of the preceding claims, wherein the production apparatus housed in a compartment comprises any one of the following equipment die-bonder, snap-cure oven, butter, strips-based plasma system wire-bonder molding machine, trim and for machine, and strip tester.
 9. A compartment according to any one of the preceding claims, wherein there is at least one access panel to the or each compartment for providing access to production apparatus inside a particular compartment.
 10. A compartment according to any one of the preceding claims, including display means for an operator to monitor production parameters, production process and/or other information to monitor the production process.
 11. A compartment according to claim 10, wherein the display means is mounted on mounting means that is slidable along the width of the compartment.
 12. A compartment according to claim 10 or 11, wherein in a production line comprising a number of compartments, the display means is slidable over the width of the combined compartments.
 13. A compartment according to any one of the preceding claims, which includes electrical trunking to supply electricity to the production apparatus within the compartment.
 14. A compartment according to any one of the preceding claims, which includes gas ducts supplying gases to a production apparatus within a compartment.
 15. A compartment according to any one of the preceding claims, wherein the cleanliness of the air within the space is maintained at class 1,000 or better. 